A fuel cell includes an anode for supplying hydrogen ions and electrons from hydrogen, and a cathode capable of supplying oxygen.
Seeing the principle of generating electricity in a fuel cell, if fuel is supplied to the anode, the fuel is ionized to generate hydrogen ions and electrons. Also, the hydrogen ion penetrates an electrolytic membrane to reach the cathode and combines with oxygen to become water. The electrons produced at the anode generate an electric current at an electric load connected between the anode and the cathode, reach the cathode, and react with the hydrogen ions and oxygen to generate water vapor.
The fuel cell is classified into a polymer electrolyte membrane fuel cell (PEMFC), a direct methanol fuel cell (DMFC), a direct borohydride fuel cell (DBFC), a solid alkaline fuel cell (SAFC) and the like.
Among the above fuel cells, the polymer electrolyte membrane fuel cell, the direct methanol fuel cell and the direct borohydride fuel cell employ a cation exchange membrane, which is a cation-conducting or hydrogen ion-conducting electrolytic membrane, as an electrolyte. Also, the solid alkaline fuel cell and the direct borohydride fuel cell employ an anion exchange membrane, which is a hydroxide ion-conducting electrolyte membrane. Here, the direct borohydride fuel cell may use both the cation exchange membrane and the anion exchange membrane.
The electrolytic membrane with ionic conductivity used in the fuel cell is an important factor for determining the efficiency and characteristics of the fuel cell, and the electrolytic membrane should have high hydrogen ion conductivity.
In addition, if hydrogen ion conductivity is irregular depending on the location of the electrolytic membrane, the current may not flow uniformly and may give adverse effects on the durability and performance of the electrolytic membrane. Thus, the electrolytic membrane should have uniform hydrogen ion conductivity over the entire region.
Therefore, it is necessary to investigate the hydrogen ion conductivity of the electrolytic membrane more precisely and miniaturize the equipment for measuring ionic conductivity of the electrolytic membrane.